Application of Photocatalytic Concrete Paving Blocks in Poland-Verification of Effectiveness of Nitric Oxides Reduction and Novel Test Method

A WO3-TiO2 nanorod/CaCO3 photocatalyst with degradation-regeneration double sites for NO2-inhibited and durable photocatalytic NO

As a promising cleaner technology for nitric oxide degradation, photocatalysis has attracted extensive attention, while the main limitations of photocatalytic nitric oxide are that the toxic NO₂ is produced easily and the photocatalytic durability was inferior due to the accumulation of photocatalytic products. In this paper, a WO₃-TiO₂ nanorod/CaCO₃ (TCC) insulating heterojunction photocatalyst with degradation-regeneration double sites was prepared by simple grinding and calcining. The effects of CaCO₃ loading on the morphology, microstructure and composition of TCC photocatalyst were investigated by SEM, TEM, XRD, FT-IR and XPS etc. Also, TCC exhibits NO₂-inhibited and durable characteristics for NO degradation. DFT calculation, the detection of active radicals by EPR, capture test and the NO degradation pathway characterized by in-situ FT-IR spectra showed that the electron-rich region formed and the existence of regeneration sites are the main reasons for promoting the NO₂-inhibited and durable NO degradation. Furthermore, the mechanism of NO₂-inhibited and durable NO degradation by TCC was revealed. Finally, TCC superamphiphobic photocatalytic coating was prepared, which still exhibits similar NO₂-inhibited and durable characteristics for NO degradation to TCC photocatalyst. It may provide new application value and development prospects in the field of photocatalytic NO.

Photoactive Cements: A Review

This article presents a short overview of modified cements with photocatalytic activity. First, the types and three main methods of obtaining photoactive cements are presented. The most frequently used modification method is the incorporation of a photocatalyst into the total mass of the cement. The second group analyzed is cements obtained by applying a thin layer of photoactive materials, e.g., paints, enamels, or TiO₂ suspensions, using various techniques. The third group is cement mortars with a thick layer of photoactive concrete on the top. In addition, methods for determining the photoactivity of cement composites, mechanical properties, and physicochemical parameters of such materials are briefly presented. Finally, examples of investments with the use of photoactive cements and development prospects are shown.